That drone flying around the Golden Dome in Montpelier on Tuesday was an attention-getter, showing that aerial surveillance of people going in and out of the Statehouse was not the stuff of action movies or science fiction.

The drone was a stunt staged by the American Civil Liberties Union of Vermont, which was highlighting the expanding reach of surveillance technology and its potential for creating an intrusive spy nation where privacy has become a thing of the past.

Public concern about government snooping has been magnified by the revelations from Edward Snowden, the former contractor for the National Security Agency, who leaked documents describing pervasive surveillance of phone records and other electronic communications. Concern about spying by the American government has become so far-reaching that this week it provoked a diplomatic snub by the president of Brazil, Dilma Rousseff, who announced she was postponing a state visit to the United States to protest the NSA spying on Brazil.

Among the concerns of the ACLU in Vermont are the potential abuse of face recognition technology and use of social media by employers to snoop on employees or prospective employees. The ACLU is pushing for legislation that would ensure that government agencies, including the police, do not get carried away by the ease with which new technology allows them to track or otherwise spy on people.

The introduction of new technology, like Snowdenís revelations about the NSA, creates a sense of unease. On the one hand, we want law enforcement and national security agencies to be able to take advantage of technologies to combat crime or to thwart enemies. At the same time, we donít want to live in a police state, subject to the feeling that we are always being watched. We are not East Germany.

These are not new problems. Soon after telephones, there were wiretaps. Yet the Fourth Amendment has always stood as a bulwark to protect citizens against unwarranted search and seizure. Our persons and effects are off limits to search unless law enforcement agencies can show a judge they have a reasonable cause for invading our privacy.

At the same time, privacy law holds that when we go out in public we surrender an expectation of privacy, at least to a degree. Someone who peeps into the window of our home and takes a photo of us would be guilty of invading our privacy. Someone who takes a picture of us as we walk down the street has not invaded our privacy.

There are many gray areas where government agencies are monitoring us. License plate recognition cameras can establish where we have been driving our cars. Our smartphones track our whereabouts. Face recognition technology used by the Department of Motor Vehicles allows agencies to identify us.

Part of the sense of unease created by a surveillance state is the premise that we all need to be monitored, that we are all potentially dangerous criminals. In contrast, the premise of a democratic state is that we are all individuals who deserve to be treated with dignity and respect. Spying on us violates our dignity.

Underlying the concern of civil libertarians is the fear that we have become the frog in the pan of water. Gradually, as our sense of privacy is eroded, the heat is rising. The fear is that, if we donít pay attention, the water will reach the boiling point, and democracy will have been sacrificed on the altar of our fears.

Legislators ought to be willing to set down guidelines protecting citizens from the rising temperature of the surveillance state, which threatens to boil us before we know it. It is not a simple task to write effective laws. Like issues of national security involving the NSA, it requires a balancing of interests. But privacy is fundamental to our dignity as individuals. How private will we feel when the sky is full of drones?